Sound-producing device



April 7, 1931. J, P, NRTHEY 1,799,387

SOUND PRODUC ING DEVICE Original Filed March l, 1929 Patented Apr. c 7, 1931 rrsr `vetres 1 JOHN r. Nostri-Inv, os'ronoNro, ONTARIO, CANADA souN'n-rnonncine envien Application nies nalen 1,` ieee, sensi No. 3453,81?. Renewed August' e1, 1930.

This invention relates to sound producing devices of the type shown in my prior Patent No. 736,428 in'which highl pressure air was used to vibratel a hollow piston in a cylinder f t having orifices in its wall7 the piston also having orifices which, by the vibration of the 'piston7 are alternately brought into and out of alinement with the orifices or" the cylinder, thus'controlling thev flow oi low pressure air to cause a rapid succession of puiis of air to produceamusical note. ,As the driving ot thefpiston requires air at high pressure, al

somewhatexpensive air compressing and cooling system has heretofore beenA necessary t5 vto provide and store such air, andthe obj ect of the present invention is to so construct the device that air at a materially lower pressure may be employed to' actuate the piston.

In the prior constructions the'hollow piston wasprovided with an enlarged head operating in a separate chamber or cylinder of greater diameter `than that or" the sound producing cylinder and the control of the driv- O ing` air was effected solelyby 'ports in the n enlarged'piston head and its cylinder wall.

The air passageswere thus of necessity of small cross sectional area-relative to their y, length so that'frictional lossesin the air were high and lag in transmission so greatthat @high air pressures were essential. i

Y In the presentinvention I'have provided "a construction in Awhich the hollow piston and its cylinder rsharein the control of the driving air to provide supplemental and more vdirect exhaustf'rombehind the piston head, Y"and also to provide supplemental 4air pasl sages from the inlet to the back of the pistonv head. Y y l l, 40 The invention is hereinafter more specificompanying drawings in which Figgl is alongitudinal section or" the apparatus; i Figy2 anenlarged sectional detail of parts of the apparatus 'showing' the piston in the i eirhaust position 'y y v l Figi-'3 a similar view showing the piston in v"the intake positiony'and' u e-L-i in rig.' 1;

intervals-as to forma musical note.v

cally described and is illustrated-in the ac-l 21 between the head 22 and thecasing;y lThe Fis-e a detail-in Ycrosssection @inthe f f s Y' `Vleisten head. has anaemia-r groove `23 toi-inedv indrical sleeve 2. rl`hewall of this cylinder "5'5 has a series ot sound producing orifices 3 Aiormed therein, which will usually be" spaced atV equal distances apart. Vlithin the cylinder a hollow piston 4 is adapted to reciprocate, this piston'be'ing also provided with sound producing` orifices 5 adapted to be brought into alinement with the orifices in the cylinder by the reciprocation ot the pis- The piston is provided with an enlargedi65 head adapted to reciproca-te in the cylinder enlargementy 7. -The apertured part of the piston is separated from the remainder oi the piston by the diaphragm 8.v The open end of the piston communicates with the horn 9, which'is suitably secured to the end fof the casing. Within the casing is formed the chamber 10 communicating with the air inletll. The sound is produced by the reciprocation ot the '.75 piston, which causes its sound producing oriiices to coincide at'regular intervals with thel orices of the cylinder 2,' thus producing a series of pud's of air which occur such f The-piston and casi-ng are constructed in .the iollowing mannerV to effect the reciprocation of the piston. vThe cylinder enlargement 7 is provided with the annular r'portsl y 12, 13,y which are connected by a plurality-B5 of longitudinal passages 25! In the wall of' the cylinder enlargement is also formed an lannular port 14. with which communicate a plurality'ot radial passages` 15 which communicate with'an annularchamberl formed vin the `casing 1. With this chamber coin-` municates the air, inlet v r17SV `Intermediate the ports 12, 13 is an annular exhaust port 18 r*with which, communicate a plurality-'otradial passages V19 which communicatek with an 5 annular chamber 20 formed-between the'casing and the cylinder enlargement and com- -municating with the `radial'exhaust passages in its exterior surface, which is so positioned that, when it forms a communication between the exhaust port 18 and the port 13, the port 12 is uncovered. Also through the head Vof the piston are formed a plurality of passages 24 opening through the forward face of the piston head and through its periphery. Preferably the inner parts of these passages are formed by an annular groove in the exterior surface of the piston head.

From this construction it follows that, when the parts arein the position shown in Fig. 2, air from behind the piston head is exhausted through the port 12, the longitudinal passages 25, the port 13, the groove 23, the exhaust .port 18, the passages 19, the'chamber 20 and the passages 21.l The momentum of the piston then carries it a little further to the Aright. There is then the condition that air under `pressure is acting on the front of the piston while the pressure has been exhausted from behind. The piston' is then forced to the position shown in nig. 3 in which the groove 23 no longer forms a com munication between the port 13 and the exhaust port 18. In this position the port 12 is sti-ll open to the space behind the piston head while the passages 24 provide-a passage for air from the space in front of thev piston head through the port 13, passages 25 and port 12 t0 the space behind the piston head. The same air pressure then exists both in front of and behind the piston head, but, owing to the greater surface-of the piston lhead exposed to air pressure at the back than at Vthe front, the excess pressure drives the piston forward to and beyond the -exhaust .position previously described. The piston is thus reciprocated to effect sound production as hereinbefore described.

The parts previously described are old in Y the'art, but to them I have now added the Y radial passages 27 communicating "with extensions 25a ofthe longitudinal passages 25. A supplementalexhaust port 28-is formed in the piston wall. This is preferably so positioned thatit comes into alinement'with the supplemental exhaust Aport 26 at or about the timefthe-exhaustport-lS isopened to the space behind the`.DSton head by'means of the groove-'23. Thus partV of the exhaust takes place-directly. Afrom the-passages 25 through the extensions 25a, the radial ypassages 27 and V-theports -26and -28-'to the interior of the hol- 10W piston where -it-1ningles with the exhaust airvpassing inwardly through-the orilices 5.

-A AsupplementalA path for air under pressure isfprovidedthroughthe-medium of the sup- .plemental inlet port 29 formed-in the cylinder wall 'andthe-groove 30 formedin the outer surface ofthe piston. This groove is of such a width that it forms a communication between the supplemental inlet port 29 and the space in front of the front wall of the piston head. The annular supplemental port is connected by longitudinal passages 31 with the radial passages 27 so that the supplemental driving air passes from the space aforesaid through the groove 30, passages 31, passages 27, the extensions 25a, the longitudinal passages 25, and the port 12 to the space behind the piston head. I find that, with the new construction, driving air at a lower pressure may be employed, thus not only elfecting economies in operation but also in the expense of installation.

What I claim as my invention is: y

1. A sound producing device comprising a cylinder having sound producing orilices in its wall; a hollow piston adapted to reciprocate in said cylinder, open at one end and having sound producing orifices in its wall adapted to be brought into alinement with the orices in the cylinder by the reciprocation of the piston; an enlarged head at the end of the piston remote from its open end; an enlargement of the cylinder in which the piston head reciprocates; an air inletand an air outlet in said enlargement; ports in the piston head and the wall of the cylinder enlargement controlling the admission and exhaust of the piston driving air; an exhaust port in the wall of the-hollow piston forming a supplemental air outlet; an exhaust port in the' cylinder with which the piston port may regisn ter; and a passage in the cylinder walls forming a communication between the last mentioned port and an exhaust passage of the cylinder enlargement.

2. A sound producing device comprising a cylinder having sound producing orices -in itswall; a hollow piston adapted to reciprocate in said cylinder, open at one end and having sound producing orifices in its wall adapted to be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; an enlarged head at the end of the piston remote from its open end; an enlargement of the cylinder in which the vpiston head reciprocates; ports in the piston headV and the wall of the cylinder enlargement'controlling the admission and exhaust of the piston driving air; an exhaust port in the wall of the hollow piston; an -exhaust port in the cylinder with which the Vpiston port may register; a passage in the cylin-der walls forming a communication between the `last-mentioned port and an exhaust passage of the cylinder enlargement; an air admission port in the cylinder wall communicating with an air admission passage leading to the back/of the piston head; and a groove 'in the piston wall adapted, when -air is being admitted behindthe piston head to form a communication between the said port and Vthe spacefin 'Vee Vfront of the piston'head, said space being in constant communication with an air supply port. v f

3; A sound producing device comprising a cylinder having sound producing orilices inits wall; a hollow piston adapted to reciprocate in said cylinder, open at onenend and having soundy producing orifices 1in lits wall adapt-ed to be brought into alinementwith the orifices in the cylinder-by the reciprocation of the piston; an enlarged head the end of the-piston remote from its open end; an enlargement of the' cylinder in which the piston head i'eciprocates; ports inthe piston head andthe wall ofthe cylinder en- Y largement controlling the admission and exhaust orp the piston driving air; and co-operating ports in the cylinder and piston walls ormingan "exhaust supplemental to that oi the piston head and the cylinder enlargement. i

4. A. sound producing device comprising a cylinder having sound producing orilices in its wall; a `hollow piston adapted to reciprocate in said'cylinder, open at one end and having sound producing oriices in its walladapted to be brought vinto alinement' with the orifices in the cylinder by the recip-y. yrocation of the piston; an enlarged head fat the end of the piston remote from its open end; an enlargement oi the cylinder in which the piston vhead reciprocates;v ports in the.

piston head and the wall of the cylinder enlargement controlling the admission and' exhaust of the pistondriving air.; co-Opelating ports in the cylinder and piston` walls forming Van exhaust supplemental to 'that of the piston head and `thecylinder enlargement; and co-'operating-ports inthe cylinder and piston walls` forming air admission means supplemental to that off'the piston head and the cylinder enlargement.

5. A; sound producing device comprising acylinder'having sound producing oriiices in its wall; a hollow piston adapted to reciprocate in said cylinder, `open at one end and having sound producing orifices in its wall adapted to be brought into alinement with the orifices yin the cylinder by the reciproca-r tion of the piston; an enlarged. headat the end of the piston remote fromits open end; v

an enlargement ot the cylinder in which the piston head reciprocates; an air port in the.

wall oit the cylinder enlargement whereby the space between the annular walls of the piston head and cylinder enlargement is constantly in communication with air under pressure; an exhaust port opening through the cylindrical wall of the cylinder enlargement; two ports opening through said wall, one at each side of thejexhaust port; a passage in the wall connecting said ports; a groove in the piston head adapted to form a communication between the forward one of said ports and the exhaust port; a passage in end and throughfits wall forward orsaid groove,7the groove and passagebeing so positioned that.when the passageforms a Coinmun'ication between the forward port and the annular space in front ofthe piston head thus'admitting air pressure behind the ypiston head the exhaust port is cut eiland when the groove is termin0F a communication between the'liorwardrport and the exhaust port, the passage is out et alinement with theformerga supplementalpassage extending from the wall passage hereinbefore mentioned and terminating in a supplemental exh austv port in .the cylinder wall; and a port in the piston wall adapted to aline with said supplemental exhaust port at or about the time the main exhaust port in the `cylinder enlargement is functioning i 6. -A sound producing device ycomprising a vcylinder having sound producingorii'ces in its wall; a hollow piston adapted tofreciprecate in said eylinder,open at one endand having sound producing orifices in .its wall adapted to be broughtinto alinementfwith the orifices in the cylinder bythe reciprocation ci' the piston; an enlarged head at the end of the piston remote from its open end; anV enlargement vof the cylinder in which the piston head reciprocates; an airport in the wall of the cylinder enlargement whereby the space between the annular walls of the piston head and cylinder enlargement is constantly Ainl communication with air under pressure; an'exhaust port opening through the cylindrical wallfjof the cylinder `enlargement; two ports opening through said wall, one at'each side of the'exhaust port ;V a passage in the wall connecting said ports; 'a groove in the piston head adapted to form a communication between the orwardone of said ports and the exhaust port; a passageV in the piston head opening through its torward end and throughyits wall forward of said groove, the groove and passage being-so positioned that, when' the passagel forms-a llO communication between the forward port and j `*the annular space inftront of the'pistoii head thus admitting ai` pressure behind the piston head, the exhaust .port is cutoff and when.: the groove iis-.forming a communication between the i'orwardv portand the exhaust port, *y

the passagev is outy of' alinement with the former; ay supplemental passage extending from the wall passage lie'reinbefore mentioned and terminating in a supplemental exhaust port-in the cylinder wall; a port .in

`the piston wall adaptedl to aline withrsaid supplemental .exhaust `port at or about-the timethe main exhaust port lin thecylinder enlargement is functioning; ak supplemental ing with the supplemental passage aforesaid;

land a. groove formed in the piston wall adaptinlet portin theI cylinder wally communieat- Y l supplemental inlet port andthe annular space in front of the piston head when air is being admitted behind the piston.

7. A sound producing device comprising a cylinder having sound producing orilices in its Wall; a hollow piston adapted to reciprocate in said cylinder, open at one end and having sound producing orifices in its wall adapted to be brought into alinement with the orifices in the cylinder by the reciprocation vof the piston; an enlarged head atthe 'ond or' the piston reinoteifroin its open end;

an enlargement of the cylinder in which the piston head reciprocates; means for supplying air under ypressure to andexhausting it directly from the cylinderenlargement to effect the reciprocation of the piston; means for supplying air under pressure to the exfu. u.

terior of the cylinder to effect sound production; andv supplemental means 'for effecting exhaust of the piston driving air to the interior of the hollow piston to mix with the exhaust Isound producing air.

8. A sound producing device comprising a cylinder having sound producing orifices in its wal-l; a hollow piston adapted to reciprocate in said cylinder, open at one' end and having sound producing orifices in its wall adapted to be brought into .alinement with vthe orifices in the cylinder by the `reciprocation of `the piston; a'n enlarged head atthe end of the piston remote from its open end; an enlargement ofthe cylinder in which ythe piston head reciprocates; means for suphaust sound 4producing air; and means controlled by the body of the pistonfor providing an additional air channel between the drivingair supply and the cylinder enlargement behind th'episton.

9. A sound producing device comprising a cylinderhaving sound producing Voriiices in its `wall; a hollow piston adapted to recipro- 'catein said cylinder, open at one end and lhaving sound producing orifices in its wall `adaptedto be brought into alinement with theorifices inthe cylinder bythe reciprocation of the pistongan enlarged head at the end of the piston remote from its open end; an enlargement of the cylinder in which the piston head reciprocates; poits in the piston headand the wall of the cylinder enlargement controlling the admission and exhaust of the piston driving air; an air admission port 1n the cylinder wall communicating with ran airadmission passage leading to the back .of the piston head; and a groove inthe piston vrmlliadaptediwhen:airis being vadmitted behind the piston head to form a communicaytion between the said port and the space in front of the piston head, said space being in constant communication with an air supply port.

l0. A sound producing device comprising a cylinder having sound producing orifices in its wall; a hollow piston adapted to reciprocate in said cylinder, open at the end and having sound producing orifices in its wall adapted t0 be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; an enlarged head at the end of the piston remote from its open end; an enlargement of the cylinder in which the piston head reciprocates; ports in the piston head and the wall of the cylinder enlargement controlling the admission and exhaust of the piston driving air; and co-operating ports in the cylinder and piston walls :forming air admission means supplemental to that of the piston head and the cylinder enlargement.

l1. A sound producing device comprising a cylinder having sound producing'oriiices in its wall; a hollow piston adapted to reciprocate in said cylinder, open at one end and having` sound producing orifices in its wall adapted to be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; an enlarged head at the end of the piston remote from its open end; an enlargement of the cylinder in which the piston head reciprocates; means for supplyingair under pressure to and exhausting it directly from the cylinder enlargement to effeet the reciprocation of the piston; means for supplying air under pressure to the eX- terior of the cylinder to effect sound production; and means controlled by the body of the piston for providing an additional air channel between the driving air supply and the cylinder enlargement behind the piston.

Signed at Toronto, Canada, this 21st day'of February, 1929.

, V JOHN P. NORTHEY. 

